检索结果-南通市图书馆

Tribological properties and tribomechanism of nickel nanoparticles in-situ synthesized in rapeseed oil

Friction 2024年第3期12卷 474-489页

作者： Wenya XU Guangbin YANG Shengmao zhang Jun XU Yujuan zhang Tianhua SUN Ningning SONG Laigui YU pingyu zhang Engineering Research Center for Nanomaterials Henan UniversityKaifeng 475004China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

Nickel(Ni)nanoparticles can be enriched on the surface of iron-based frictional pairs,which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-active nano-additives *** this paper,nickel acetylacetonate was used as a precursor to in-situ synthesize nickel nanoparticles with an average diameter of about 12 nm in rapeseed oil(RO)as the reducing agent,surface modifier,and solvent as *** tribological properties of the as-synthesized Ni nanoparticles were evaluated with a four-ball tribometer,and their tribomechanism was investigated based on the characterizations of the tribofilm on rubbed steel surfaces by the scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).It was found that the Ni nanoparticles in-situ prepared in the RO with a mass fraction of 0.3%can reduce the wear scar diameter(WSD)of the steel ball by 36%.This is because,on the one hand,the Ni nanoparticles are adsorbed on the rubbed steel surfaces to repair or fill up the micro-pits and grooves *** the other hand,Ni nanoparticles participate in tribochemical reactions with atmospheric O and steel substrate to form the tribochemical reaction film on the rubbed steel surfaces with the assistance of friction-induced heat and applied normal *** addition,an amorphous carbon film is formed on the rubbed surface via the carbonization of base oil under the catalysis of Ni *** adsorbed Ni layer,the tribochemical reaction film,and the carbon layer comprise a composite tribofilm composed of amorphous carbon,polar fatty acid,metallic nickel,iron oxides,and nickel oxides on the rubbed steel surfaces,which contributes to significantly improving the antiwear ability and load-carrying capacity of the RO for the steel-steel sliding pair.

关键词： nickel(Ni)nanoparticles rapeseed oil(RO) in-situ synthesis tribological properties tribomechanism

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

比卡鲁胺配位铂的合成及抗肿瘤活性

引用

深圳大学学报（理工版） 2024年第4期41卷 463-470页

作者：陈育婷王浩冰张平玉深圳大学化学与环境工程学院广东深圳518071

铂类药物是一类在临床上应用广泛的抗癌药物,其毒副作用和耐药性仍是亟待解决的难题.为提高铂类药物的药效和抵抗单一药物的耐药性,将铂配合物与临床抗肿瘤药物比卡鲁胺配位偶联,成功制备了一种能够进行肿瘤光动力治疗的新型铂类配合物(... 详细信息

铂类药物是一类在临床上应用广泛的抗癌药物,其毒副作用和耐药性仍是亟待解决的难题.为提高铂类药物的药效和抵抗单一药物的耐药性,将铂配合物与临床抗肿瘤药物比卡鲁胺配位偶联,成功制备了一种能够进行肿瘤光动力治疗的新型铂类配合物(platinum-bicalutamide,Pt-BIC),通过核磁共振和质谱表征目标配合物;采用9,10-蒽二基-双(亚甲基)二丙二酸单线态氧探针检测发现,在550 nm的光照条件下Pt-BIC能够产生强氧化性的单线态氧(^(1)O_(2)),进而氧化细胞内的还原型辅酶I(nicotinamide adenine dinucleotide reduced coenzyme I,NADH),破坏NADH和烟酰胺腺嘌呤二核苷酸/辅酶I(nicotinamide adenine dinucleotide,NAD^(+))的氧化还原平衡状态;采用噻唑蓝比色法测定Pt-BIC对肿瘤细胞的光毒性,结果表明,Pt-BIC的抗肿瘤活性优于单一顺铂和单一比卡鲁胺;采用2′,7′-二氯荧光素二乙酸酯(2′,7′-dichlorofluorescin diacetate,DCFH-DA)探针检测发现,Pt-BIC在550 nm光照条件下能够促进细胞内活性氧的产生.研究工作不仅为新型铂类药物的设计和开发提供了新策略,也为癌症治疗带来新希望.

关键词：生物化学光动力治疗抗肿瘤药物铂配合物比卡鲁胺还原型辅酶I

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

中蒙俄高铁可达性及其空间效应

引用

经济地理 2024年第6期44卷 13-21页

作者：初楠臣孙永胜张平宇哈尔滨师范大学地理科学学院黑龙江哈尔滨150025 河南大学黄河文明与可持续发展研究中心暨黄河文明省部共建协同创新中心河南开封475001 中国科学院东北地理与农业生态研究所吉林长春130102 中国科学院大学资源与环境学院北京100049

文章以中蒙俄经济走廊西线、东线铁路为对象,在高速铁路情境下,利用可达性指标测度沿线城市可达性的动态变化,研究了线路升级提速后对沿线区域和城市的空间效应。研究发现:(1)未来中蒙俄高铁的运行使得沿线可达性大幅提升,高铁1 d交流... 详细信息

文章以中蒙俄经济走廊西线、东线铁路为对象,在高速铁路情境下,利用可达性指标测度沿线城市可达性的动态变化,研究了线路升级提速后对沿线区域和城市的空间效应。研究发现:(1)未来中蒙俄高铁的运行使得沿线可达性大幅提升,高铁1 d交流圈覆盖全线,东线的可达性及其改善程度略强于西线。(2)中国城市可达性强于俄罗斯和蒙古国城市,表现出“东南高、西北低”的格局特征。蒙古国城市可达性改善程度大于中国和俄罗斯城市,呈线路“中间高、首末低”的格局特征。(3)高铁可达性的提升加速沿线格局的演变和重塑。人口和经济重心向中蒙俄高铁轴带迁移,极化效应凸显;高铁轴带内部边界效应消失,一体化效应显现;走廊沿线贸易创造和转移效应加深,同走廊外的跨境投资规模增大。

关键词：可达性 “一带一路” 经济潜力跨境贸易中蒙俄经济走廊高铁轴带边界效应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Revitalizing Old Industrial Base of Northeast China:Process, Policy and Challenge

引用

Chinese Geographical Science 2008年第2期18卷 109-118页

作者： zhang pingyu Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China

Northeast China is the largest old industrial base of China that endured persistent influence of the past planned economy system. This region has lost its leading place since the reform and opening up, and became a backward region by contrast with the coastal areas. This paper elaborates the evolutionary process of the old industrial base of Northeast China, analyses the main reasons for the decline, gives a preliminary evaluation on the revitalizing polices in recent years, and points out major long-term challenges for future revitalization. It concludes that for Northeast China, a relative declining area: 1) it is indispensable to get the long-term policy support from the central government; 2) system reform and structure adjustment are the crucial strategies, particularly the reform of the large and medium state-owned enterprises; and devel-oping new industries is as important as upgrading traditional advantaged industries; 3) the local governments should play an indirect role, avoiding from any unnecessary intervention on economic activity; and 4) social security and investment climate must be improved simultaneously. In addition, the author stresses that the lack of knowledge on the nature of old industrial base had led to failures of the past initiatives, and revitalizing the old industrial base should be treated as a holis-tic regional project including economy growth, society progress and environment improvement.

关键词： old industrial base regional revitalization regional policy Northeast China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simulation Analysis on Spatial Pattern of Urban Population in Shenyang City,China in Late 20th Century

引用

Chinese Geographical Science 2011年第1期21卷 110-118页

作者： QIN Zhiqin zhang pingyu Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

The spatial distribution of urban population can reflect significantly urban functions and development status. Shenyang, as a typical old industrial city in China, has experienced considerable changes in spatial distribution of population in the process of urban transformation, resulting in the change of urban spatial structure. Based on the sub-district data of Chinese national population censuses in 1982, 1990 and 2000, this study simulates the evolution pattern of spatial distribution of urban population in Shenyang City. Using statistical method and exploratory spatial data analysis (ESDA), we found that the population distribution, on the whole, has presented a balanced and decentralized trend since the 1980s, which characterizes with Chinese suburbanization. Furthermore, based on the investigation of the pattern of population distribution, it is concluded that the negative exponential model fitted the distribution best, and population concentration in the inner suburb kept increasing gradually, meanwhile, the spatial structure of population distribution has presented a polycentric feature since the 1980s. The parameters of the model show that population in the urban core concentrate significantly all the time. The increase of population in the inner suburb influences the population distribution pattern more and more importantly, but the concentration intensity of population cores in inner suburb is still low.

关键词： population distribution urban spatial structure simulation analysis Shenyang City

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

中俄边境地区外贸企业资本分布的影响因素及尺度效应

引用

经济地理 2024年第2期44卷 102-111页

作者：李雨欣张平宇杨奇峰初楠臣中国科学院东北地理与农业生态研究所吉林长春130102 中国科学院大学资源与环境学院北京100049 哈尔滨师范大学地理科学学院黑龙江哈尔滨150025

文章以中国东北的中俄边境地区为案例区域,基于县域单元从微观视角刻画了外贸企业资本分布的时空演变特征,并构建空间计量模型、MGWR模型重点探讨了不同因素对外贸企业资本分布的作用程度及尺度效应。结果表明:①2011—2021年中俄边境... 详细信息

文章以中国东北的中俄边境地区为案例区域,基于县域单元从微观视角刻画了外贸企业资本分布的时空演变特征,并构建空间计量模型、MGWR模型重点探讨了不同因素对外贸企业资本分布的作用程度及尺度效应。结果表明:①2011—2021年中俄边境地区外贸企业的资本规模呈现先快速增长后缓慢下降的变化趋势。其中批发零售企业和制造企业的资本规模始终最高,但在俄远东地区市场环境的冲击下,二者增长率自2015年开始逐渐下滑。②外贸企业的资本规模在2011—2021年呈现整体集聚、局部扩散的演变格局,并表现出多核心的结构形态。其中批发零售企业的路径依赖特征显著,呈现极化发展的沿边分布模式;制造企业则不断向内陆地区扩张,形成“沿边—腹地”产业协同态势。③从“全球—地方”视角来看,边境地区对国际地缘形势、国内开放政策和地区发展禀赋高度敏感。其中与外贸企业活力直接相关的微观变量作用尺度更小,与企业所处经济环境相关的宏观变量作用尺度更大。④不同类型企业资本布局具有独特的区位、政策和环境偏好。其中批发零售企业具有较强的市场敏感性和资本活跃性,因此企业资本根植于地区开放程度、市场潜力以及融资能力;制造企业的资本分布受产业集聚和制度性力量的驱动,工业基础、第二产业及交通条件的影响十分显著。

关键词：外贸企业资本分布尺度效应 MGWR模型中俄边境

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Iridium photosensitizer constructed liposomes with hypoxia-activated prodrug to destrust hepatocellular carcinoma

引用

Chinese Chemical Letters 2023年第4期34卷 110-115页

作者： Shuangling Luo Chao Liang Qianling zhang pingyu zhang College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Hypoxic tumor microenvironment is a major challenge for photodynamic therapy(PDT). To overcome this problem, PDT combined hypoxia-activated chemotherapy is a promising strategy for hypoxic cancer therapy. Herein, a multifunctional liposome(AQ4N-Ir1-sorafenib-liposome) is prepared by encapsulating a hypoxia-activated prodrug AQ4N, a photosensitizer iridium(III) complex and hepatocellular carcinoma(HCC) targeting drug sorafenib, for synergistic therapy of HCC. Ir1-mediated PDT upon irradiation induces ROS generation and hypoxic environment, which leads to the disassembly of the liposome and activates the antitumor activity of AQ4N. Meantime, the co-delivered sorafenib could effectively target therapy of HCC. It is noted that ferroptosis mechanism is proved during the treatment. This work contributes to the design of hypoxia-responsive multifunctional liposome for combination of chemotherapy, targeting therapy and PDT. It is a promising strategy for hypoxic HCC therapy.

关键词： Hypoxia activation Iridium photosensitizer Ferroptosis Photodynamic therapy Chemotherapy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influences of deposition parameters on the microstructure and properties of nanostructural TiN films synthesized by filtered cathodic arc plasma

引用

Rare Metals 2005年第4期24卷 370-375页

作者： zhang Yujuan YAN Pengxun WU Zhiguo zhang pingyu Laboratory for Special Functional Materials Henan University Kaifeng 475001 China Department of Physics Lanzhou University Lanzhou 730000 China

Titanium nitride （TIN） films with nanostructure were prepared at ambient temperature on a （111） silicon substrate by the filtered cathodic arc plasma （FCAP） technology with an in-plane ＂S＂ filter. The effects of deposition parameters on the grain size, texture and nano-hardness of the films were systematically investigated. The grain size was obtained through calculation using the Scherrer formula and observed by TEM. The results of X-ray diffraction and electron diffraction indicated that increasing either negative substrate bias or argon flow promoted the formation of （111） preferred orientation. High argon flow leads to biaxial texture. The micro-hardness of the TIN films as a function of grain size showed a behavior according to the Hall-Petch relation under high argon flow.

关键词： inorganic nonmetallic materials titanium nitride deposition nanostructure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Variation Character of Grain Yield per Unit Area in Main Grain-producing Area of Northeast China

引用

Chinese Geographical Science 2007年第2期17卷 110-116页

作者： CHENG Yeqing zhang pingyu zhang Huimin Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Based on the surveys and the statistic data during 1980-2003, the variation character of grain yield per unit area in Northeast China and its main factors have been discussed by the methods of statistics and grey correlation analysis. The results show that: 1) the grain yield per unit area has been taking on an increasing trend in the recent 20 years. It increased from 2519.80kg/ha in 1980 to 4216.11kg/ha in 2003, with an increasing rate of 67.32%; 2) the variation of grain yield per unit area is considerably prominent and its range is also very great, with the maximal increase rate of 42.59% and maximal decrease rate of 21.13%, respectively, which are far above the whole Chinese average level; 3) the variation of main crops' yield per unit area is remarkable, which takes on the character that the yield of corn is much higher than that of soybean and rice; and 4) the grey correlation analysis shows that the most important factors impacting the variation of grain yield per unit area are the total power of agricultural machinery, the consumption of chemical fertilizer and effective irrigated area. However, the influence of natural disaster and income level should not be ignored. Effective ways to improve grain yield per unit area are to construct farmland improvement groundwork, reclaim the middle- and low-yield farmland, etc.

关键词： grain yield per unit area grey correlation analysis Northeast China main grain-producing area

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Population Shrinkage in Resource-dependent Cities in China: Processes, Patterns and Drivers

引用

Chinese Geographical Science 2020年第1期30卷 1-15页

作者： LI He Kevin LO zhang pingyu Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China Department of Geography Hong Kong Baptist UniversityKowloon Tong999077Hong KongChina College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Resource-dependent cities(RCs)are a vulnerable group of urban settlements that often face population shrinkage;however,population changes in RCs in China are not well *** study offers new insight into this matter through a robust analysis that features a longer time scale,a larger sample of RCs,and a finer unit of *** finds new evidence that problems of population shrinkage in RCs are more serious than previous literature has *** 30%of the studied units have experienced either long-term or short-term population shrinkage,and many more are experiencing a slowing down of population *** are especially common among three types of RCs:the resource-depleted RCs,the forestry-based RCs,and RCs in Northeast *** results underscore transition policy inadequacies in addressing population loss,and call for a more comprehensive and diversified population policy that tackles the multifaceted factors that contribute to population shrinkage,including lack of industrial support,maladjustment to market oriented reformation,poor urban environment and natural population decline.

关键词： resource-dependent cities urban shrinkage population change urbanization,China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：